Re: [dm-crypt] cryptsetup

[Milan Broz <mbroz@redhat.com>]

f-dm-c@media.mit.edu wrote:
> Shouldn't there be a "cryptsetup resize" in there somewhere?
> [Presumably before you resized the ext2]

There is no device size stored in LUKS header, only data offset.

So after luksClose/luksOpen the device has always new size, of course
if you increase size extended part of device still contains old data.

You can also resize device online - just use "cryptsetup resize <name>".
(The --size parameter is not mandatory, man page is wrong here,
if --size is not provided, it will expand to whole device).

So if you have LUKS on partition, and you want extend it: 
extend partition -> resize crypt mapping (or deactivate/activate) -> resize fs

For reducing just do it in reverse order
resize fs -> deactivate cryptsetup -> reduce partition.
(if you need it online, you will have to specify --size for cryptsetup resize,
note that --size is in sectors)

Milan
--
mbroz@redhat.com